The History and Technology of the Edison Bridge & Driscoll Bridge

THE LLoouuiiss BBeerrggeerr GGrroouupp, IINC.

East Orange, New JerseyNew JJersey DDepartment oof TTransportation

Trenton, New Jersey

The HHistory && Technology

of tthe

Edison BBridge && DDriscoll BBridgeover tthe

Raritan RRiver, NNew JJersey

Morris GoodkindChief Bridge Engineer - New Jersey Highway Department

1925-1955

Morris Goodkind was born in New York Cityin 1888 and graduated from ColumbiaUniversity in 1910 with a degree in civilEngineering. Following school, he workedwith the city of New York preparing plans forthe subway system. He joined the engineeringfirm of Albert Lucius in 1912 as an assistantengineer. Lucius had engineered elevatedrailway systems for New York and Brooklynin the late 1800s, and was specializing in thedesign of railroad bridges when Goodkindjoined him. Goodkind worked in Lucius'soffice between 1912 and 1914, andundoubtedly it was here that his interest andskills in bridge design were first honed.

During his early career years, Goodkindmoved between jobs in the public and privatesector. He worked for New York's InterboroRapid Transit Corporation and the J.G. WhiteEngineering Corporation. From 1919 to 1922,he worked as county bridge engineer forMercer County, New Jersey.

In 1922, Goodkind joined the New Jersey Highway Department as general supervisor of bridges. Hewas named Chief Bridge Engineer in 1925, a position he held until his retirement in 1955. Hereceived numerous awards and honors for his work over the course of his career with the state. Hismost prestigious bridge award was the Phoebe Hobson Fowler Medal, given by the American Societyof Civil engineers for his design of the College Bridge, a multi-span concrete arch carrying U.S.Route 1 over the Raritan River. The bridge has since been renamed the Morris Goodkind MemorialBridge.

Goodkind also won several "most beautiful bridge of the year" awards, given annually by theAmerican Institute of Steel Construction. Among the winners were Oceanic Bridge over theNavesink River (1940); Passaic River Bridge between Newark and Kearney (1941); and AbseconBoulevard Bridge in Atlantic City (1946). During World War II, Goodkind consulted for the WarDepartment, aiding the Army Corps of Engineers in bridge design and construction. He was awardedthe Tau Beta Pi Achievement Certificate from Rutgers in 1948 and an honorary Doctor ofEngineering degree from Newark College of Engineering in 1950. He served as Consulting BridgeEngineer for the building of the Garden State Parkway in the early 1950s. After retirement from theHighway Department in 1955, he was a partner in the firm of Goodkind and O'Dea, which currentlyoperates under the name of Dewberry-Goodkind, Inc. In 1958, Goodkind was granted the EgelstonMedal by Columbia University, their highest award for engineering achievements. Morris Goodkinddied September 5, 1968.

Morris Goodkind (facing camera) inspecting construction of Edison Bridge, 1939.

Construction of the Edison Bridge, 1940.Source: New Jersey Department of Transportation.

The History & Technologyof the

Edison Bridge & Driscoll Bridge over the Raritan River, New Jersey

Copyright © 2003 New Jersey Department of Transportation

Printed in the United States of America.

This document was written by Richard M. Casella and Julius Haas, and edited andproduced by Susan D. Grzybowski, C. Carol Halitsky, and Hope E. Luhman of

THE Louis Berger Group, INC., East Orange, New Jersey.

INTRODUCTION

The Route 9 Edison Bridge and Garden State Parkway Driscoll Bridge cross the Raritan River together to form one of New Jersey's most vital highwaylinks. Barring accidents or construction, as many as 275,000 vehicles per daycross these two bridges, making them perhaps the heaviest traveled twinbridges in the world.

The route across the Raritan between Perth Amboy and South Amboy has beenimportant since the state's earliest days. In 1684, Radford's Ferry provided thelink for the stagecoach line between New York and Philadelphia. For over 200years, ferries shuttled travelers across the Raritan.

In 1875, Perth Amboy and South Amboy were joined by a bridge for the firsttime with the construction of the New York and Long Branch Railroad Bridgeacross the mouth of the Raritan River. The line ran from Long Branch to PerthAmboy, where it made connections with branches of the Pennsylvania and theCentral New Jersey railroads. This new line was instrumental in the furtherdevelopment of seaside resorts along the Jersey shore in Monmouth and Oceancounties and was soon transporting hordes of summer beachgoers.

Victory Bridge, in foreground, is a swing bridge, pivoting on a center pier to allow boat traffic to passthrough two channels. Opening the bridge in the summer resulted in huge traffic backups. EdisonBridge, west of the Victory, was built high enough to allow all vessels to pass under. Source: NJDOT

2

The railroad bridge stalled the construction of a highway bridge over the mouthof the Raritan River until 1910, when a "county bridge" was erected with adrawspan in the middle. Within a few years, it was inadequate to handle thetraffic and the weight of increasingly larger trucks. Calls for a new bridge,which began in 1916, were answered ten years later by the Victory Bridge.

Again the anticipated traffic loads were grossly underestimated. No one couldhave predicted that the number of car registrations in the United States wouldtriple during the 1920s to 23 million. The Roaring Twenties might well havebeen named for the sound of overheated cars and drivers heading to the Jerseybeaches over the Victory Bridge on a typical summer weekend. Hordes of newcar owners had discovered the joy of motoring to the beaches. To make mattersworse, the increase in pleasure boating, also on the weekends, led to morefrequent openings of the Victory Bridge. It was apparent to the locals that asecond bridge, not a replacement, was required, and that it must be a fixedbridge, high enough for any conceivable vessel to pass freely under.

The History and Technology of the Edison Bridge & Driscoll Bridge

Beach traffic on the Victory Bridge–visible in the background–in the late 1930s. Source: NJDOT

Over the Raritan River, New Jersey 3

THE EDISON BRIDGE

The Edison Bridge was the centerpiece of a limited-access highway arounddowntown Perth Amboy, officially referred to as "Route 35 Extension from theWoodbridge Cloverleaf to Keyport," but known to most as the Perth AmboyBypass. The roadwork began in 1935 with the re-routing of Route 35 and Route 4 from Victory Bridge into a new traffic circle in South Amboy. InAugust, 1938, the state legislature approved $4 million in funding for the bridgeproject, and officially named it the Thomas A. Edison Bridge. A Federal grantfrom the Public Works Administration covered 45 percent of the total cost.

The design of the Edison Bridge was the direct responsibility of MorrisGoodkind, chief engineer of the bridge division of the New Jersey StateHighway Department, a position he had held since 1925. Goodkind had a well-established national reputation. Two of his monumental bridge projects, CollegeBridge, carrying U.S. Route 1 over the Raritan River and built in 1929, and thePulaski Skyway, a high-level viaduct and bridge system over the Passaic andHackensack rivers, completed in 1932, had earned international attention (seearticle below on Morris Goodkind). Goodkind oversaw the preparation of plansand drawings for the bridge by his staff, most notably bridge designer W.F.Hunter and chief draftsman, L.C. Petersen. The engineering firm of Ash,

Source: NJDOT

The History and Technology of the Edison Bridge & Driscoll Bridge4

Howard, Needles and Tammen of New York City consulted on the design andreviewed the plans.

The location chosen for the new highway and bridge was 3,000 feet to the westof the Victory Bridge. The federal requirement of a minimum of 135' ofclearance under the bridge for navigation meant that long approaches would berequired to keep the road grade within acceptable limits. In a bold move,Goodkind and his engineering team agreed on a design calling for the longestand heaviest deck plate-girder highway bridge ever built in the United States.The deck girder bridge type had become the first choice of engineers for long-span highway bridges owing to its economy, ease of construction, and otherpractical features (see article below on bridge technology).

The final design called for a bridge with 29 spans and an overall length of4,391 feet. The nine spans over the river would consist of three continuous spangirders of record-setting proportions. The main girder over the navigationchannel would be 650' in length, consisting of a 250' span flanked by two 200'spans, and would set a new U.S. record for length. The two other continuousgirders were each 600' in length, consisting of three 200' spans. Theunprecedented design posed unique problems and challenges to the bridgebuilders. As firms specialize in different aspects of construction, and theengineers wanted to ensure the most competition and lowest price for thebridge, the project was divided into six separate contracts: the river piers, theriver pier shafts, the south approach piers, the north approach piers, structuralsteel, and the concrete deck and lighting systems. The most complicated andexpensive parts of the project were the river piers and the structural steel.

The Peter F. Connolly Company won the two contracts for the river piers andshafts and began work on September 26, 1938. The massive amount of concreterequired for the huge piers to support the bridge at such a great height over theriver called for special equipment and techniques that Connolly developed (seephoto caption). The contracts for the north and south approach piers, whichwere relatively straightforward to construct, were won by the J.F. ChapmanCompany and the Folhaber Pile Company, respectively. The concrete deck andlighting contract was awarded to the John G. English and Joseph NestoCompany.


Far more challenging was the job of fabricating and erecting the structural steelfor the bridge. The only bridge builders capable of the job were divisions of thenation's two largest steel manufacturers: American Bridge Company, a part ofU.S. Steel Corporation, and Bethlehem Steel Company's Fabricated SteelConstruction Division. Bethlehem won the contract and built the steelwork intheir Pottstown, Pennsylvania, plant.

The fabrication, shipment, final assembly, and erection of the bridge girdersinvolved many unusual problems because of their unprecedented weight,length, and depth. Special railcars were built for the haul from the factory toJersey City, and even then the massive girders cleared the rail by only 4" andthe overhead power lines by only 5". For safety, the electricity was shut down,and a diesel locomotive was utilized. At Jersey City, the girders were loaded oncar float barges for delivery by water to the bridge site.

Construction of the ten massive concrete river piers and shafts required special floating equipment,designed and built for the job by the contractor, the Peter F. Connolly Company. A floating derrick wasmodified to reach 150' to the top of the piers. Cement was delivered by rail to a waterside track wherea separate derrick boat transferred it to a floating barge. A screw conveyor and bucket elevatortransferred the cement to a floating concrete plant, which mixed the batches and discharged the wetconcrete onto a system of belt conveyors. Connolly also developed a novel method for preassemblingthe steel reinforcing for the pier shaft inside formwork that was then lifted into place by a tall crane.The contractor's work was featured in an article entitled "Unusual Equipment Speeds Caissons andPiers", which appeared in Engineering News Record magazine. Source: NJDOT


The 600' and 650' continuous girders built to span the river were completelyassembled at the plant and then disassembled into seven pieces to enableshipment by rail. The pieces were then field spliced at the construction site toform three huge sections, the largest of which was 260' in length and weighed198 tons, a world record. Mr. C.L. Lane, assistant manager of erection forBethlehem Steel Company, supervised the erection of the superstructure, whichbegan on September 1, 1939, and took slightly over 14 months to complete.

The first step in erecting the steelwork was the setting of the simple spangirders for the approaches. This work was accomplished simultaneously fromboth ends using a combination of land cranes and traveling cranes, calledtravelers, which rolled on rails mounted directly on the girders. As each pair ofgirders was placed, the rails were extended, and the traveler moved forwardtoward the river. The larger of the two travelers had a capacity of 125 tons, waspowered by a 300-horsepower engine, and weighed 260 tons. The northapproach consisted of six 85' spans and six 155' spans, while the southapproach consisted of eight 135' spans.

Lifting the main girders in place set a new heavy-lift record in the U.S. The final cost of thebridge was $4,696,000. More than 65,000 cubic yards of masonry, 50 percent buried fromsight, went into the foundations, piers, and deck of the bridge. Over 2,500,000 pounds ofreinforcing steel and 19,000,000 pounds of structural steel were used. Source: NJDOT


The erection of the 260' long, 200-ton sections of the river spans required thedesign and construction of one of the world's largest floating bridge-erectionderricks. The floating derrick was assisted in lifting the river spans by the 125-ton capacity traveler. To prevent bending in the girder during the lift, ahorizontal stiffening truss was attached to the girder and remained in place untilthe girder pairs were joined together with floor beams.

The 260' girders could not be lifted into place if there was the slightest wind,and bad weather resulted in numerous delays. The first girder was successfullylifted into place on the morning of March 14, 1940, establishing the new heavy-lift record. The bracing system functioned perfectly. Several hours later, duringthe lift of the second girder, its bracing system failed, and the top flangebuckled approximately three feet out of alignment. The girder was lowered tothe barge and used again after it was straightened and determined suitable foruse.

Upon completion of the steelwork, the concrete deck was laid, and railings andlighting were installed. On November 20, 1940, the bridge was permanentlyopened to traffic. During the course of construction, three workers were killedin falls from the bridge.

The Edison Bridge was dedicated SaturdayDecember 14, 1940. The ribbon was cut byMrs. Mina Edison Hughes, widow of theinventor, shown above with State SenatorJohn E. Toolan, Governor A. Harry Moore,and Governor-elect Charles Edison, son ofthe inventor, and Morris Goodkind.Roughly 1,150 people, including adetachment of 650 soldiers from Fort Dix,attended the dedication. State HighwayCommissioner E. Donald Sterner declaredthat the bridge, situated in a state whereone-third of the nation's key industrieswere located, was a vital link in thenational defense program. Source: NJDOT


THE DRISCOLL BRIDGE

The creation of the New Jersey Highway Authority in 1952 included a mandateto construct the Garden State Parkway as quickly as possible to relieve theincreasing traffic congestion in New Jersey. A centerpiece of the project was thebridge carrying the Parkway over the Raritan River at Perth Amboy. Named forAlfred E. Driscoll, New Jersey Governor from 1947 to 1954, it is the largest ofthe Parkway's nearly 300 bridges, and one of the state's busiest, carrying anaverage of over 200,000 vehicles per day.

The Driscoll Bridge was designed as a nearly identical twin of the EdisonBridge because of the channel clearance requirements set forth by the U.S.Department of the Army. With jurisdiction to determine the minimum heightand width of bridges over navigable waterways, the U.S. Army Corps ofEngineers required that the 135' height and 250' channel span specified for theEdison Bridge fourteen years earlier would also apply to the Driscoll Bridge. Afurther condition, that the channel piers of both bridges share a common fendersystem, resulted in the new bridge being located just 175 feet west of theEdison Bridge. This ensured that navigation and river currents would not beimpeded by an excessively long fendered channel or by a second restrictedchannel a short distance away.

Whatever difficulties these requirements posed for the Parkway's planners wereoffset by benefits to the bridge engineers. With the bridges so close together, itwas logical for both aesthetic and practical reasons that they be twins withessentially the same engineering and architectural features. The highlysuccessful and record-setting Edison Bridge provided a full-scale model withplans and records from which the details of design, fabrication, erection, andcost of the new bridge could all be extrapolated.

The design and construction oversight of the Driscoll Bridge was the result of acollaboration between three groups of engineers: the New Jersey HighwayAuthority staff, the consultants to the Authority for the overall Garden StateParkway project, and the bridge design firm of D.B. Steinman of New YorkCity.


Harold W. Griffin, chief engineer of the New Jersey Highway Authority, carriedoverall responsibility for the Driscoll Bridge project and was assisted by HarryA. Hartman, supervisor of construction. The firm of Parsons, Brinkerhoff, Hall& McDonald served as general consultants for the Parkway project, and MorrisGoodkind served as consulting bridge engineer for the Parkway's bridges.Goodkind was chief bridge engineer at the New Jersey State HighwayDepartment at the time and had been responsible for the design of the EdisonBridge fourteen years earlier.

David B. Steinman was one of the world's leading bridge engineers at the timeand was chosen for his particular experience with long-span plate-girderbridges. Steinman and his partner, Holton D. Robinson, pushed the limits ofbridge materials and engineering, and designed many of the early record-settingsuspension bridges during the 1920s and 1930s. The firm of Robinson andSteinman had designed the Charter Oak Bridge at Hartford, Connecticut,completed in 1942, which held the title as longest plate-girder bridge in theUnited States until 1951, when the twin New Jersey turnpike bridges over thePassaic and Hackensack rivers were completed.

Construction of the Garden State Parkway (GSP) beganin 1946 after passage of New Jersey's Parkway andFreeway Act. The GSP was started as part of the statehighway system and was initially funded with annualhighway appropriations. By 1950, with only ten miles ofthe parkway's 165-mile route opened, it became apparentthat with only annual appropriations, the project mighttake 40 years to complete.

In April 1952, the legislature created the New JerseyHighway Authority to build, maintain, and administer theGSP using state-backed bonds to be paid back with tolls.When voters overwhelmingly approved the projectreferendum in the November election, the Authoritybegan construction on a large scale. By the end of 1953,$140 million in construction contracts had been awarded,and the construction of 177 of the GSP's 282 bridges wasproceeding rapidly along.

The 165-mile-long parkway was designed to connect thenorthern metropolitan areas and southern coastal areas.With more than 200 entrance and exit ramps, it wouldlessen congestion on local roads along the way. The GSPwas built to move New Jersey drivers around their state,in contrast to the Turnpike, which was built with very

few exits, and channeled interstate traffic in one end andout the other.

In addition to the 13 engineers on staff, the HighwayAuthority assembled a team of 24 of New Jersey'sleading engineering consultants and firms. The engineersemployed state-of-the-art highway and bridge planningand design technology. Features to accommodate futuretraffic needs were "built-in," such as banked curves tosafely handle speeds up to 70 miles per hour, and widemedians and shoulders for additional travel lanes. Extraconcrete foundations were even added to allow forbridges to be widened. This feature saved taxpayersseveral million dollars when the bridge was widened in1972.

The Raritan River Bridge was finished three monthsahead of schedule in July 1954, and the GSP, beinglargely completed, was officially opened on October 23,1954, by Governor Meyner. In May 1956, with theopening of the Great Egg Harbor Bridge, the parkwaywas complete. The nine-mile extension joining the GSPto the New York State Thruway was added in 1957. TheRaritan River Bridge has since been renamed after AlfredE. Driscoll, governor of New Jersey from 1947 to 1953.

The Garden State Parkway


The robust economy and suburban housing boom that followed World War IIresulted in not just one car in every garage, but two, and a multitude of newtrucks for every commercial purpose.

Nowhere was the impact of all these vehicles felt more than on New Jersey'shighways. But New Jersey's drivers were long acquainted with traffic jams,dating from the early days of the automobile when beach traffic backed up inlegendary proportions. Geographically positioned as New England's gateway,the Garden State also suffered from large and ever-increasing numbers ofinterstate travelers and commerce just passing through. To many it seemed thattraffic could only get worse. And so, in the early 1950s, with the good timesrolling, taxpayers embraced heavy investment in highways that would carrythem far into the future. New Jersey was ready to lead the way, and the GardenState Parkway would be a standard bearer.

With no opportunity for record setting, the Driscoll Bridge project wasessentially a "bread-and-butter job" for Dr. Steinman. As part of a major newhigh-capacity highway system, it did, however, call for the best practice indesign, materials, and construction to ensure long, efficient service. Notable inthis regard were special structural features to allow economical widening of the

Driscoll Bridge Evolution. The bridge was originally built with two 30' concrete roadways, a 5' center mall, andtwo 2' emergency walkways to accommodate four 15' wide lanes of traffic. In 1957, the deck was re-striped toaccommodate six 10' lanes. Between 1970 and 1972, a third set of columns was added, resting on the founda-tions built for them in 1955, and the superstructure was widened from six lanes to ten lanes. In 1984, the timbermedian barrier was replaced with a concrete barrier to provide six lanes of traffic in each direction. Source:Gronquist 1955.


bridge to meet future traffic demands, and a state-of-the-art concrete deck.Building bridges has always been one of the most expensive publicundertakings. Although the great initial cost justifies some additional expensesto ensure long life, the public generally cannot accept expensive over-designingfor estimated future traffic loads. Bridges are normally bottlenecks because theycannot be economically equipped with wide shoulders and breakdown lanesneeded for maximum traffic flow. It was therefore considered significant at thetime that not only was the Driscoll Bridge designed with unusually wide travellanes and broad shoulders, but that a major investment was made in buildingextra foundations for a third roadway to be built sometime in the future.

The second special feature of the Driscoll Bridge was the design of the concretedeck, which provided for the latest advances in construction methods andequipment. Efficient techniques developed three years earlier for building thedecks of the huge New Jersey Turnpike bridges over the Passaic andHackensack rivers were studied and incorporated into the design of the DriscollBridge. The attributes of good engineering– great speed, high quality, andeconomy–had all been achieved.

In designing the 7" thick concrete deck for the Driscoll Bridge, the engineersstarted with the specifications used by the New Jersey State HighwayDepartment and then turned their efforts to achieving the smoothest possibleriding surface. The use of structural-steel continuous-drain curbs, and steelgrating for the sidewalks and center mall, simplified the concrete work. Thewalks provided workers easy access for construction of the bridge deck. Thecurbs served as a fixed support and guide on which to slide the deck screed andpersonnel bridges that were used in spreading and smoothing the wet concrete.

The steel curbs were set in place with precision and closely inspected by thefield engineers for uniformity. The finishing of the concrete deck requiredseveral steps: a vibrating screed, mounted on wheels that rode on the curbing,was pulled over the fresh concrete. This was followed by a wood float and thena straight-edge scraper, operated by two men from a pair of rolling bridgesspanning the fresh pavement. Wet burlap cloth was then pulled across thesurface, and the final finish was produced with a stiff bristle broom. The resultwas a nearly mile-long concrete surface that was considered as perfect as couldbe constructed.


The superstructure of the Driscoll Bridge was fabricated and erected by theBethlehem Steel Company, the same contractor that built the Edison Bridge. Asthe Driscoll Bridge was a structural copy of the Edison Bridge, Bethlehem Steelhad the necessary patterns for duplicating the girders and the equipment andexperience for efficiently erecting the bridge. The construction process wasessentially the same: the girders were assembled in the company's Pottstown,Pennsylvania, plant, transported by special railcars and barges to the site, andlifted with enormous cranes into place.

One improvement in the construction process was in the temporary stiffeningtruss attached to the girders to prevent lateral buckling during lifting andsetting. During the lifting of the main girder for the Edison Bridge, the heaviestlift in the world at the time, the girder buckled slightly. The improved stiffeningtruss used high-strength bolts, torqued to a minimum tension of 25,600 lbs. TheDriscoll Bridge was completed in July 1954, three months ahead of schedule.

Specially built to be easily widened tomeet future traffic demands, the DriscollBridge was cited for its progressive designand was featured on the cover of the April1955 Civil Engineering magazine. Shownis the lifting of the massive 263' maingirder, weighing over 200 tons, fabricatedand erected by the Bethlehem SteelCompany.



Historic Photos of Edison Bridge and Driscoll Bridge.


THE DESIGN AND TECHNOLOGYOF CONTINUOUS PLATE-GIRDER BRIDGES

The Edison and Driscoll bridges are continuous plate-girder deck bridges. TheEdison Bridge is historically important as a large and early example of its type.It marked an important step in the development of the modern continuous plate-girder highway bridge in America, which began about 1932. The DriscollBridge, a duplicate of the Edison Bridge and built twelve years later, wassignificant for its special structural features that allowed the latest advances inconstruction methods and equipment to be used in laying its concrete deck andprovided for the economical widening of the bridge at a later date to meetfuture traffic demands.

When completed, the Edison Bridge not only exceeded common engineeringpractice but set records in the United States for its type and for bridge buildingpractice. It was the largest and highest girder bridge in the United States, andshared the record for longest girder span with a bridge in Charleston, WestVirginia. (The Charleston Bridge was begun after the Edison Bridge, but wascompleted sooner owing to its much smaller overall size.) The placing of themain-span girders of the Edison Bridge on piers 135' above the Raritan Riverinvolved the lifting of the world's longest (260'), heaviest (198 tons), anddeepest (20'-6") girder ever erected in the United States. Special train cars,barges, and cranes were constructed to transport and erect the girder.

The first plate-girder bridge in America was a simple-span structure ofwrought-iron construction, erected for the Baltimore and Susquehanna Railroad.Plate girders were widely adopted by the railroads for spans of up to 100', andby the early 20th century, constituted all but a small percentage of short spanrailroad bridges. Although less efficient in terms of materials, railroadspreferred plate girders to trusses for numerous reasons: simple design anddurability; ease of construction, shipment, and erection; higher mass andrigidity and therefore less sensitivity to vibration; and suitability for use inpositions of small clearance. Railroads had the means to ship the girders in onepiece and derrick cars for lifting and setting the girders in place.

A continuous beam (or girder) is a solid beam supported at three or more pointsalong its length and designed to carry a greater load than a simple beam of the


same size and span. Trusses, plate girders, and box girders can all be madecontinuous. The structural advantage of a continuous beam over a simple spanresults from bending forces created in the beam over the piers, whichcounteract and reduce the bending forces in the center of the span. Among thepractical advantages are economy of material, increased rigidity, and theconvenience of erection without falsework. Fewer bearings and expansionjoints and shorter approaches as a result of reduced girder depth are otherdesirable features. When continuous beams were first put into use, someengineers believed that there were structural advantages to making more thanthree spans continuous, but it was later proven that no increase in rigidity wasobtained with more than three spans.

The continuous girder originated in Europe, with minor examples built forrailroads in Germany, France, Switzerland, and Austria as early as 1835. The

Typically I-shaped in cross-section, a plate girder originally consisted of a rectangular steel plate (theweb) riveted to parallel pairs of top and bottom angles (the flanges) to form a deeper beam than can beproduced in a steel-rolling mill. Steel cover plates were joined to the top and bottom flanges, andvertical angles–called angle stiffeners–were joined to the web plates at regular intervals for additionalstrength. Advances in welding methods by the 1950s eliminated rivets. Without rivet holes, whichreduced strength, a single, heavier plate could be used. Stiffeners are still used but consist of narrowplates welded in place.


first large continuous bridge was the Britannia Bridge over the Menai Straits inEngland, built in 1848 by Robert Stevenson. It was a four-span tubular plate-girder (box-girder) bridge with two 460' and two 230' spans and carried railroadtracks through it. This remarkable bridge held the plate-girder record until thebuilding of the 528' Frankenthal Bridge at Cologne, Germany, in 1939. Anotherlong-span tubular iron railroad bridge was built by Stevenson over the St.Lawrence River at Montreal in 1854-1860, but it was so expensive that thedesign was never adopted by American engineers.

From the late 19th century through the 20th century, continuous girders wereused by American railroads for short-span bridges, viaducts, and elevated linesand widely applied in steel-frame building construction. Plate girders wererarely used for highway bridges: they were too difficult to haul over countryroads, and even the lightest designs greatly exceeded the strength necessary tocarry the small live loads of early road vehicles. Even the railroads could notreadily transport and handle plate girders in one piece much beyond 100' inlength.

Trusses on the other hand were much lighter, used less steel than a plate girderfor a given span, and could be assembled at the plant and disassembled forshipment. The first continuous truss bridge in the United States was a double-track railroad bridge spanning the Ohio River at Sciotoville, built by GustavLindenthal in 1917. The twin 775' spans of the bridge shattered the previousworld record of 472' for a continuous truss bridge.

As the nation's roads and highways were improved and extended during theteens and twenties to meet the exploding population of motor vehicles,engineers first turned to inexpensive and easily erected concrete bridges or lightthrough truss bridges. The Germans were the first to begin applying thecontinuous plate girder to long-span highway bridges, beginning in the early1920s. They built a two-span continuous-girder bridge over the Neckar River atMannheim in 1926 with spans of 282' and 180', a design that far exceededanything Americans would build for nearly two decades. German engineersadvanced plate-girder technology through the 1930s and 1940s, outdistancingthe rest of the world in terms of number of bridges and length of span.

In the United States, it was not until the 1930s that a number of factors cametogether that led to the rapid development and adoption of the continuous plate-


girder highway bridge. In1929, Yale engineeringprofessor Hardy Crosspublished his famousmoment distributionmethod for the analysis ofcontinuous frames andbeams. At roughly thesame time, mechanicaland photoelastic methodsfor checking stresses incelluloid, metal, or glassmodels of complexstatically indeterminatestructures were

developed. Models enabled designers to visualize the behavior of every part ofthe structure under various conditions of loading and correlate the observationsto analytical results. As metallurgical research provided a better understandingof the elastic properties of steel, engineers overcome their fear of reversalstresses in continuous girders and a sharp increase in their application soonfollowed.

The deck bridge also became the preferred form for highway bridges during the1930s as the speed and number of automobiles increased, and the advantages ofthe type became more apparent. As opposed to a through bridge, a deck bridgeprovides an unobstructed view, creates less anxiety in the motorist from feelinghemmed-in, and allows greater speed and safety because the optical illusion ofa narrowing roadway is nearly eliminated.

Bridge engineers within state highway departments became the chiefproponents of the continuous plate-girder deck bridge. The economicdepression forced states to stretch their road budgets, and the new bridge typewas proving to be the most economical solution for most elevated and medium-span highway bridge applications.

Articles appeared in engineering journals describing the successful use ofcontinuous plate-girder bridges in Kansas, Georgia, Nebraska, and Montana.The Kansas highway department built over fifty continuous bridges between

Many bridges were replaced in the 1930s and 1940s to accommodate thenew heavy trucks.


1933 and 1935 and reported that the savings over simple span structures wereestimated at between 10 and 30 percent, covering the increased engineeringcost many times over. In addition to savings on steel, joints, and bearings, thegreater rigidity of these bridges reduced deflections and allowed shallowerconcrete deck construction. More costs were shaved by reducing the size of thepier caps and eliminating some end floor beams. By the end of the decade, moststate highway departments were on the bandwagon.

A landmark in the development of the modern long-span continuous plate-girder bridge in the United States was the construction of the Capital MemorialBridge in Frankfort, Kentucky, by the State Department of Highways in 1937.The 200' main span was the longest of its type in the U.S., and with a depth ofonly 12' at the supports and 7' at mid-span, it approached the maximumtheoretical slenderness ratio. Its gracefully curved bottom chords won it the"most beautiful bridge of the year award" in its class from the AmericanInstitute of Steel Construction. Although more expensive to fabricate, curvedbottom chords decreased deflections on longer girder spans with the addedbenefit of a more pleasing appearance.

The year 1938 was another banner year for continuous plate-girder bridges inthe U.S., marked by a series of records set and broken. A 217' span wascompleted at Topeka, Kansas, while work commenced on a 220' span atTallulah Falls, Georgia, and 250' long spans at Charleston, West Virginia, andPerth Amboy, New Jersey. The editors of Engineering News-Record called plategirders the most notable development in steel bridge design for 1939, citing theEdison Bridge as "the first and only long high-level plate girder in the countrywith a layout which hardly would have been considered suitable for plategirders even a few years ago."

Although it shared the record for span length with the Charleston Bridge, theEdison Bridge was of monumental class (bridges over $1 million in cost) withextraordinary features. The 52' wide roadway accommodated five lanes oftraffic. The Charleston Bridge was two lanes wide. The much larger live anddead loads required massively deep and heavy girders, which at 250' long and21' deep over the supports, were the largest in the country.

Just six months after completion of the Edison Bridge, a new span record of271' was set by the Main Avenue Bridge in Cleveland. Although the bridge was


also notable for its use of several all-welded rigid frames in the approaches, itscamouflaged rockers, and the use of models to analyze the girder design, it didnot approach the magnitude of the Edison Bridge.

Setting the next record came at a very high price. One of the worst accidents inbridge building history occurred during the erection of the Charter Oak Bridgeover the Connecticut River at Hartford in 1941. Designed by the renownedbridge engineering firm of Robinson and Steinman, the 300' center span and270' side spans formed a continuous girder, 840' in length. Temporary supportsunder the bridge collapsed during the erection of the center span. Thirty-twoworkers and engineers along with 470 tons of steel and a 176-ton travelingcrane—the largest in the country—fell 100' into the river. Sixteen men werekilled and the rest were critically injured. The engineering community focusedon the ensuing investigation. When it was conclusively demonstrated that thecause of the accident lay in the erection methods used by the American BridgeCompany and was not related to an "over bold design," construction quicklyresumed. The bridge was completed as designed and opened without furtherincident.

The onset of World War II brought a halt to bridge building in the UnitedStates, except for bridges deemed essential to the war effort. Ironically, theeffects of the war would ultimately improve and speed the course of futurebridge design here and abroad. The war destroyed more than 8,500 ofGermany's bridges and left the world—especially Europe—with an enduringshortage of steel and other building materials. German engineers sharpenedtheir pencils and quickly perfected theories proposed in the 1920s governing atype of bridge-deck design in which the steel girders and stringers of thesuperstructure were rigidly bonded to a continuous steel-plate floor. Building

The Bonn-Beuel Bridge over the Rhine River, 1949, with a center span of 643', was the longest continuous plate-girder bridge in the world at the time. The four girders, 36' deep at piers, were rigidly attached to the dishedsteel plate and concrete slab deck to form an early orthotropic design known as a tonnenbleche deck. Source:Troitsky 1968.


such "grid system" floors became possible with the development of welding.Eventually known as orthotropic bridges, these lightweight designs used lessmaterial and allowed far greater spans. By combining orthotropic deck designsand high-strength alloy steels,the Germans made huge leapsforward in continuous girderbridge technology. In 1948,the Cologne-Deutz Bridgeestablished the new recordwith a 610' main span flankedby a 435' and a 396' span.Longer spans followed inrapid succession.

Back in the United States, thewar-induced structural steelshortage persisted into the1950s, making modernreinforced concrete designslike rigid-frames, andprestressed concrete, alogical choice for short- tomedium-span bridges. Butsteel prevailed for long spans,and as the post-war nation embarked on the building of thousands of new roads,parkways, turnpikes, and thruways, much of which became the interstatehighway system, the plate girder was called back into service.

In 1952, the New Jersey Highway Department again led the nation by buildingtwo record-setting continuous plate-girder bridges, each with center spans of375', for its huge New Jersey Turnpike project. The 375' span represented anincrease of 25 percent over the Charter Oak Bridge, a large jump made moreinteresting by the fact it was accomplished by different engineers usingdifferent methods for each bridge. Ammann & Whitney, engineers of thePassaic River Bridge, followed accepted American practice specified by theAmerican Association of State Highway Officials (AASHO). The engineers ofthe Hackensack Bridge, Howards, Needles, Tammen & Bergendoff, adopted theEuropean practice of placing more of the required flange area in the cover

Thirty-five Years Experience Not Enough. Construction ofHartford Bridge, shown less than a minute before collapsing intothe Connecticut River. In charge was W.J. (Jim) Ward, ErectionSuperintendent for American Bridge Company. Over his 35-yearcareer, Ward erected many of this country's great bridges. Wardand 15 others died in the collapse, blamed on the temporary piles,visible in the photo, which snapped off below the mudline. Source:Engineering News-Record.


plates, in this case 77 percent, which represented a substantial increase over the60 percent specified by AASHO. New Jersey was back in bridge engineeringheadlines in 1954 with the building of the Driscoll Bridge, the longest bridge

on the new state-of-the-art Garden State Parkway.Connecticut and D.B.Steinman, however, didnot rest. In 1958, thecountry's most prominentpracticing engineer onceagain took the title for thelongest continuous plate-girder bridge in Americaback to the Nutmeg State.Just 12' longer than thetwin New JerseyTurnpike spans, the Q-Bridge, as it becameknown, carries theConnecticut Turnpikeover the Quinnipiac Riverat New Haven.

German engineers,however, had alreadyadvanced plate-girdertechnology way beyondthe Q-Bridge with thecompletion in 1956 of theSave River Bridge inBelgrade, Yugoslavia, athree-span continuousorthotropic design with amain span of 856'. This

record stood until 1972 when the Rio-Niteroi Bridge over Guanabara Bay,Brazil, was opened. With a center span of 984' and an overall length of 45,604'(over 8 miles), the Niteroi Bridge remains the longest continuous plate-girderbridge in the world.

New Jersey Recaptures Plate-Girder Record. The New Jersey Turnpikebridges over the Passaic and Hackensack rivers were built as twins–notidentical–but each with a main span of 375'. It was a new record for acontinuous plate-girder bridge in the U.S. and in the case of theHackensack span, it marked the adoption of more progressive Europeanplate-girder bridge designs. The placing of the last section of the centerspan of the Hackensack Bridge is shown above on the cover of theJanuary 17, 1952 issue of Engineering News-Record.


PLATE-GIRDER BRIDGE AESTHETICS

The importance of building beautiful or at least aesthetically pleasing bridgeshas been promoted since the Renaissance. Discussion of bridge aesthetics waslimited to the characteristics of masonry arches erected throughout capitals ofthe world until the mid-19th century when new materials and methods weredeveloped for heavy railroad bridges. The adoption of steel for bridgeconstruction in the 1860s led to the building of huge truss and suspensionbridges that were occasionally the subject of architectural criticism.

In America in the late 19th and early 20th centuries, the drastic need for bridgesfor rails and roads outweighed concerns about artistic design. To engineers andtheir paying customers, the bridge design that performed its intended purposesimply and with the least material and cost was the best design. Functionality,as engineers called it then, was considered pure and inherently beautiful in itsown right, springing from the miracle of man's intelligence and his mastery ofscience and mathematics. Functionality combined with paternal pride to ensurethat nearly every bridge, when opened and dedicated by its fathers and patrons,was declared beautiful.

And many of America's bridges were undeniably beautiful: the natural beautyof the arch and the catenary when rendered in steel had produced the Eads St.Louis Bridge and the Brooklyn Bridge, hailed as both engineering andarchitectural masterpieces. But the architecture of these bridges and the othergreat steel-arch, truss, and suspension bridges of the time was in the stoneworkof the towers, anchorages, piers, and abutments. The steel superstructure, on theother hand, was described by one critic as "a mathematical skeleton, sketched inwith scanty steel along their lines of stress."

American bridge engineering treatises have included extensive sections on theaesthetic design of bridges since the late 19th century. Bridge designers wereinstructed to consider the fundamental principles of artistic design in the orderof their importance: symmetry, style, form, dimensions, and ornamentation.Occasional commentaries on the elements of good aesthetic design and beautyas they pertained to bridges appeared in the engineering press in the early 20thcentury, but for the most part critics were kept busy disparaging the


proliferation of new architectural styles and cheap machine-made buildingmaterials.

The first major schism in the philosophy of bridge architecture and aestheticsbegan in 1920 following a story in Engineering News Record about the ornatelydecorated Bensalem Avenue Bridge, built in Philadelphia. A nasty war waswaged in a series of articles, editorials, and letters over the relationship betweenart and structures, between architects and engineers, and over who was morequalified to make such judgements.

Foremost among the causes of the dispute was the rapid development andadoption of reinforced concrete bridges for the nation's expanding highwaynetwork. Moldable into virtually any shape or form, economical, and well-suited to arches, concrete at first ushered in a nostalgic return to the classicismand heavy decoration found in earlier bridges crafted of stone. But a symbioticrelationship quickly developed between concrete and the new architecture ofModernism, promoted by Frank Lloyd Wright, Le Corbusier, Mies van derRohe, and others. Functionality meshed with Machine Age philosophy tobecome Functionalism expressed in Modernistic concrete bridges. Thetraditionalists and the progressives were at each others throats.

Longing for the days of stone, renowned "old school" bridge engineer GustavLindenthal weighed in with an article in Scientific American in 1926 entitled"Some Aspects of Bridge Architecture." Dr. Lindenthal found fault with nearlyeverything that was happening in the bridge business but had specialvehemence for the current art of steel bridge building: "there is no thought ofarchitecture, or of durability or of pride in the art. . . the most naked utilitarianconsiderations are allowed to govern the design. . . it has become acommercialized trade which has been prostituted, under the pretense ofscientific economy, to the production of the cheapest structures that will carrythe loads."

Meanwhile, concrete bridge technology advanced, stretching bridges into longdelicate arches or molding elements into highly stylized Classical, Art Deco,and Modern forms. Each year, increasingly stupendous and unarguablybeautiful concrete bridges were going up. By 1929, the structural steel industryhad had enough. The American Institute of Steel Construction (AISC)established an award to be given annually to the "most esthetic solution to a


problem in steel construction." The first award went to the 6th StreetSuspension Bridge in Pittsburgh, completed in 1928. In 1930, the AISC gavethree awards based on a bridge's cost: Class A, over $1 million; Class B,$250,000-$1 million, and Class C, less than $250,000. The press coined theterm "most beautiful steel bridge of the year award," which stuck.

Because of their ability to carry loads of massive weight and size, plate-girderbridges were used almost exclusively by the railroads up until the late 1920s.When used for highway bridges, the most common application was for railroadoverpasses. Plate girders were easily delivered by rail and dropped into placeby a derrick car. They were utilitarian in the strictest sense, regarded either asunattractive or as an epitome of functionalism, but mostly they were politelyignored.

Federal programs to eliminate dangerous road and track crossings at grade inthe late 1920s led to an increase in the use of plate-girder bridges, particularlyin urban areas. Possibly the first effort to "beautify" a plate girder was made bythe Westchester County Parks Commission in 1929. Jay Downer, engineer forthe commission, designed a deck plate-girder highway bridge with an arched

The Edison Bridge did not win any aesthetic awards, but its design was true to the doctrine of functionalism inwhich Morris Goodkind strongly believed. By the late 1930s, the era of adding extraneous decorative details tobridges was over. Clean lines, graceful curves, linear shadow lines, and the repetition of simple shapes such asfloor beam extensions to support the sidewalks and the vertical stiffeners of plate girders, were viewed asaesthetically pleasing representatives of the "pure form" of engineering science. The bottom chord of the girderswas left flat and deepened at the supports, distinguishing it from the more expensive curved type that waswinning appearance awards. Source: NJDOT.


web and bottom flange (or chord) to span railroad tracks in Mt. Pleasant, NewYork. The bridge won the AISC award that year for most beautiful short-spanbridge, apparently a first for the homely plate girder. New Jersey followed suit,winning the AISC award in 1933 for a multi-span plate-girder and basculebridge over the Shark River, also with curved bottom chords. Although moreexpensive to fabricate, the curved bottom chord on deck plate girders decreaseddeflections on longer spans and provided a more pleasing appearance.

Bridge aesthetics played an important role in the New Jersey HighwayDepartment under its chief bridge engineer Morris Goodkind. Goodkind and hisdesign staff had an eye for good aesthetics and captured many AISC awardsover the years, beginning in 1932 with the Pulaski Skyway bridges.

The discussion of bridge aesthetics came to fruition in the 1930s and was due inpart to the AISC awards, which rekindled the old debates on what constitutedgood aesthetic bridge design and what role, if any, architects should play. In1934 Harry Engle, a bridge engineer with the firm of Mojeski, Masters andCase in Philadelphia, dropped the first bomb with an article called "Art inBridge Building," published in Civil Engineering. Engle believed infunctionalism, that "bridges should be ornamented only to emphasize the designconceived by the engineer" and that "beauty is inherent in a properly andscientifically designed structure." Engle pointed to the towers of theWashington Bridge where the masonry facing was left off for economy and thegrowing opinion was that the bare steel possessed a "Machine Age beauty" thatadded to rather than detracted from their appearance. He concluded that designsof true beauty must originate with the engineer, leaving the architect only in therole of a collaborator to contribute to the attractiveness of the final design.

Arthur J. Lichtenberg, a bridge designer with the New Jersey State HighwayDepartment, fired off the first letter of protest, stating "it does not necessarilyfollow that a structure designed by an engineer will possess the elements ofbeauty simply because it is functional." Lichtenberg concluded that the bestinterests of the public would be served if the engineer and architect collaboratedfrom the inception of the design. This opinion was expressed in most letters andpapers on the subject that followed over the years.

In February 1935, at the annual convention of the American Concrete Institute,Morris Goodkind presented a comprehensive paper entitled "Architectural


Considerations in Bridge Design." Goodkind had obviously put great thoughtinto the subject, stressing the importance of aesthetics while offering manyspecific do's and don'ts: "of primary importance is that the bridge express truth. . . its parts should exhibit a clear explanation of its purpose. . . the masking ofsurfaces or the members without visible justification or the use of lines foreignto the structural design leave a false impression and should be avoided aslacking artistic worth. . . efforts to imitate materials such as stone by the use ofscorings in concrete surfaces should be discouraged as being deceptive. . .essential to a beautiful structure is simplicity. . .meaningless ornamentation andembellishment merely detract attention from important features and serve toirritate rather than please the observer." Goodkind's paper covered all aspects ofthe subject in a systematic, no-nonsense fashion that, when the paper waspublished, left critics completely and mysteriously silent.

Numerous other important papers on bridge aesthetics were published in the1930s, most notably those by engineering professors J.K. Finch of Columbiaand Leslie Schureman of Princeton, by Wilbur J. Watson, a consulting engineerand author of the 1926 landmark book Bridge Architecture, and by AymarEmbury, an architect and engineer who collaborated as architectural consultantwith D.B. Steinman and others on several major bridge projects.

No one had anything to say about plate girders, however, except the AISC,which continued to give them awards. A notable advance in the aesthetics andtechnology of the plate-girder highway bridge in the United States wasdemonstrated by the Capital Memorial Bridge in Frankfort, Kentucky, built in1937. It was the longest continuous plate girder in the United States, and itsgracefully curved bottom chords achieved nearly the maximum theoreticalslenderness ratio, earning it the AISC award in its class for that year.

World War II stalled discussion of bridge aesthetics, but the post-war buildingboom of highway bridges brought it back to the forefront. In 1949, theDepartment of Architecture at the Museum of Modern Art in New Yorkundertook a study of bridge architecture in an effort to raise the quality ofAmerican bridge design. The resulting book, The Architecture of Bridges, waswritten by the Department's curator, Elizabeth B. Mock, and published with agrant from the American Bridge Company, a subsidiary of U.S. SteelCorporation. Mock found the plate girder "immobile and a bit dry" and "likelyto seem gross" in long heavy spans, "but a good simple elementary form,


orderly and restful . . . pleasantly unobtrusive but notably elegant." Mockstresses that "because of its lack of structural drama the plate girder more thanany other bridge depends upon justice of proportions and perfection of detail."

Over the second half of the 20th century, the continuous deck girder bridgebecame one of the most widely used bridge types in the world. Germanimprovements in deck designs led to thinner and longer girders with gracefullyarched bottom chords of undisputed beauty. The discourse on bridge aestheticscontinues today as new bridge forms are developed and grand old bridges arereplaced.


AESTHETIC AND TECHNOLOGICAL CONCEPTSFOR THE NEW ROUTE 9 SOUTHBOUND BRIDGEAND THE REHABILITATION OF THE EDISON BRIDGE

After 62 years of service without a major reconstruction, the Edison Bridge wasin need of complete redecking and rehabilitation. In order to maintain trafficflow along Route 9 during rehabilitation and improvement of the existingsubstandard bridge geometry, the New Jersey Department of Transportation(NJDOT) decided to build a new bridge, parallel to the Edison Bridge.

In June 1999, NJDOT awarded a contract for the construction of a newsouthbound bridge. The new bridge was constructed in the space between theEdison and Driscoll bridges. It was configured to first carry both bounds ofRoute 9 traffic in order to permit closing of Edison Bridge for rehabilitation.Upon completion of rehabilitation, the Edison Bridge was converted to carrynorthbound traffic only. The newly constructed bridge carries Route 9southbound traffic.

Edison and Driscoll bridges had created a certain visual order through thenumber and length of their spans, the locations of their piers, their profiles, andtheir superstructure types. Although not identical, their pier shapes are similar.The Edison Bridge had two-column piers while Driscoll Bridge had three-column piers. The detailing and shapes are also similar but not identical as theintricate details of concrete construction used in the 1930s were not used orreplicated in the 1950s.

The contemporary design selected for the new southbound bridge applies 21st-century techniques and technologies, and yet it is visually compatible with bothexisting structures.

As a result, the pier locations and span length of the new bridge replicated thatof the Edison Bridge. The new bridge, however, was designed to be lower thanthe Edison Bridge, providing a more gradual vertical profile in order to improvestopping sight distance and thus enhancing traffic safety on the bridge.

The piers were constructed as two-column piers without a mid-height strut asmodern design techniques do not mandate its use. The columns were


constructed more economically of uniform and smaller rectangular sections.Nevertheless, the bases of the piers were designed with steps to replicate theornamental base of the Edison Bridge piers, and haunches were introduced atthe top of the columns for functionality and to provide a visual transition fromcolumn to horizontal cap beam.

The river piers of the Edison Bridge and the Driscoll Bridge were protected bygranite stone masonry against ice and other objects that might float by. Thepiers of the new bridge are protected with high performance concrete, a mixturethat offers enhanced durability and strength. However, to visually complementthe look of stone masonry, a recently developed technique that uses formlinersto texture and shape concrete surfaces was used to create the appearance ofgranite masonry protection.

Modern design and construction techniques were also used in the superstructureand deck construction of the new bridge. Both existing bridges wereconstructed of two main steel plate girders and steel floor beams with bracketsand steel stringers. The design for the new bridge, however, uses a structurallyredundant framing system that provides back-up support for the roadway.

The new bridge spans over the river were designed with continuous steel plategirders of three main girders with two substringers supported by cross frames.The main girders were seated on top of the pier cap beam by means ofmultirotational bearings.

Girders were of prismatic design and approximately 8' in depth, except for ataper needed for transition to a girder depth of 10' in the span above thenavigation channel. This system was found to be most economical for thenumber and length of river spans. However, for the somewhat shorter approachspans over land, a girder framing system using prestressed concrete wasselected.

Essentially five lines of prismatic girders, approximately 6.5' deep were used inthe bridge superstructure over the land north and south of the river. The girderswere of precast prestressed construction and were made continuous by post-tensioning to form two units of continuous girders at the south and at the northapproach spans respectively. At the north end, where the spans were longer(155' to 173'), a technique of spliced girders was used. The girders consisted of



Garden State Parkway and Route 9 Bridges after Widening of Route 9 Note lower profile (top), pier changes (middle), and framing (bottom).


pier units and center portion units erected by means of a temporary steelsupport (strong back). The units were spliced (connected) into a continuousmonolithic unit—again by post-tensioning. The girders were also integrallyembedded in the cast-in-place pier cap, thus forming monolithic connectionbetween substructure and superstructure. To achieve this, the pier caps andgirders were post-tensioned transversely also.

These construction techniques were possible because of the modern high-capacity tall cranes that were operating in the narrow space between theexisting bridges and the high-strength materials that permitted the design ofeconomical and relatively light bridge components.

Rehabilitation of the existing Edison Bridge presented a different engineeringchallenge. The aim was to replace the entire superstructure with one of moderndesign that could be safely supported by the existing substructures. The verticalprofile was lowered to match that of the new southbound bridge and to improvestopping sight distance. To achieve this, some of the piers will be cut shorter toaccommodate the new superstructure. The aesthetic and technological aspectsof the rehabilitation design are discussed below.

The most memorable aspects of the Edison Bridge as originally built were theshapes, proportions, and fine details of the superstructure, piers, and abutments.When built, the bridge reflected the highest standards of bridge design andcraftsmanship current in the years between 1890 and 1940 in this country.

The overall aesthetic goal for reconstruction of the Edison Bridge was tomaintain the proportions and details of the original bridge where reasonable,and to incorporate proportions and details reflective of the original bridge intothe new elements. The result demonstrates how traditional craftsmanship andattention to detail can be married with modern materials to create an example ofthe bridge builder's art as attractive and memorable as the original.

Superstructure

The bearing stiffeners and the shapes of the main channel span haunchespresented the major opportunities to emulate the quality of the originalsuperstructure. The superstructure was notable for the haunches formed byreverse curves at the longer spans and for the detailing of stiffeners and


brackets throughout, which created an intricate geometric girder pattern. Themain channel haunches of the new superstructure are created with reversecurves that are similar to the original haunches. Triple stiffeners are used at thebearings to recall the stiffeners of the original bridge and also create a patternon the girders which reflects the grooved rectangle on the pier just below.

The rehabilitated Edison Bridge remains a steel plate-girder bridge, but modernwelding and design techniques have reduced the need for stiffeners. The rebuiltbridge uses a five-girder system rather than the two-girder system of theoriginal bridge. The five-girder system reduced the required depth of thegirders, removed the need for brackets, and now provides the structuralredundancy necessary to ensure back-up support for the bridge.

Piers

The piers of the Edison Bridge were notable for their fine proportions, whichremained consistent from the tallest to the shortest pier, as well as for the cornerindents, setbacks, and inset panels that were worked into the surfaces. Thedetails remained impressive because of the excellent condition of the originalconcrete, which had aged to a beige color and had weathered to a uniformtexture resembling coarse sandpaper.

An especially notable detail was the rectangle with three or five verticalgrooves that occurred at the apex of each pier. The rectangle was sizedproportionally at each pier according to the overall dimensions of the pier. This repeated feature drew the eye along the profile from pier to pier, visuallyhighlighting the points of weight transfer from girder to pier.

Because of the combined effects of the shallower superstructure and the needfor a lowered profile grade over the channel, all of the Edison Bridge pierswere rebuilt at a different height. Some had to be raised as much as 10', andsome had to be lowered.

The concept for the rebuilt piers incorporated a new standard of pier top in theshape of an inverted U and consisted of the new pier cap and short sections ofthe columns with a haunch (tapered section) on the inside face of the columns.The haunch reflects the new structural function of the pier cap and establishesan obvious visual break at the point where the original columns were cut. The


Garden State Parkway and Route 9 Bridges after Widening of Route 9.Note imitation of granite masonry at pier base (bottom).


depth of the pier cap and length of the column haunch were established byreference to the depth of the horizontal strut of the original pier. This assuredthat the proportions of the rebuilt pier were consistent with the proportions ofthe original pier.

Decorative elements of the existing piers, particularly the grooved rectangle,were replicated and incorporated into the rebuilt piers. These decorativeelements are constructed of precast concrete that is colored and textured tomatch the color and texture of the existing piers. The rest of the new pier capand haunch sections have the natural color of new concrete.

The dimensions of the decorative elements were adjusted at each pier to fit thepier's proportions. The color and texture of the decorative elements connectsthem with the historic portions of the bridge and differentiates them from thenew structural elements.

The outer girders of the new five-girder system are set slightly outside of theoriginal girder locations. Small cantilevers were required at each pier tosupport these girders. Decorative elements based on original decorativeelements helped to integrate the small cantilever required by the new outergirders into the overall form of the piers.

Abutments

The most notable features of the abutments were the Art Deco end-blockpilasters with patterns of glazed tile on the exterior surfaces. Because theroadway of the rebuilt superstucture is slightly narrower, it was not necessary tomake any changes to these pilasters.

The only change to the abutments that was necessary was to add narrowpilasters along the abutment faces to support each of the five girders. These arethe color of new concrete, again differentiating new structural elements fromthe historic bridge. However, since the new pilasters were placed within theexisting end-block pilasters, as seen against the face wall, they are relativelyinconspicuous.


Railings and Light Poles

The new Route 9 Southbound Bridge and the rehabilitated Edison Bridge areseen together by travelers on both bridges. Visual compatibility of the bridgeswas enhanced by coordinating the placement and color of the railings and lightpoles between the two bridges.

The four-rail galvanized and painted railing on the Edison Bridge matches therailing on the new Route 9 Southbound Bridge. The railings on both bridgesare blue, which blends well with the blue and gold frieze on the abutment endblock of the Edison Bridge.

The same gray light poles and fixtures are used on both bridges. The lightpoles on both bridges are laid out with the spacing symmetrical about thecenterline of the main channel span. This places the poles into a consistentrelationship with the major piers.

Colors

The colors of the Driscoll Bridge and the Route 9 Southbound Bridge areshades of gray, which would have been compatible with almost any colorchosen for the Edison Bridge. As the Edison Bridge conceals the other twobridges from view when looked at from the east, and the other two bridges hidethe Edison Bridge in views from the west, the color of the Edison Bridge didnot need to be restricted by the color of the other bridges.

Since the superstructure of the Edison Bridge is new, there was no compellingreason to use black, which is the historic color of the bridge. However, thecolors in the original glazed tile work—blue, gold, and light red—suggested thechoice of blue for the deck elements.

Aesthetic Advantages

The new superstructure of the Edison Bridge is different in depth and shapefrom that of the new Route 9 Southbound Bridge. While both land and riverspans of the Edison Bridge are steel, the land spans for the Route 9 SouthboundBridge are concrete, and its river spans are steel. Although there are differencesbetween the bridges, the following aesthetic advantages have been realized:


In general, built elements should reflect the technology andmaterials of the time when they are built. High-strengthconcrete and steel, and new methods of computerized analysisare now available and lead to forms quite different from theforms of sixty years ago. As an entirely new bridge, the Route9 Southbound Bridge reflects these forms.

The rehabilitated Edison Bridge also reflects the times in whichit was built. The past achievements of technology are preservedin its substructure design, and advances that have been madesince the bridge was built are evident in its new superstructure.

Because the Route 9 Southbound Bridge is not visible fromimportant downstream viewpoints, views of the complementarydesigns of the Edison Bridge and the Driscoll Bridge arepreserved.

When viewed from the east, the Edison Bridge will stand outamong the trio of bridges. Height differences among thebridges will allow the viewer to appreciate the slendersuperstructure and well-proportioned piers of the EdisonBridge.

The combination of the Edison Bridge, the Driscoll Bridge, andthe new Route 9 Southbound Bridge tells the story of bridgeconstruction over the last sixty years. The rehabilitated EdisonBridge recalls a bridge of the 1930s, the Driscoll Bridge isillustrative of a bridge of the 1950s, and the new Route 9Southbound Bridge represents a bridge of the 21st century.


BRIDGE TERMINOLOGY & GLOSSARY

Abutment: a structure, usually stone or concrete, that supports one end of a bridge spanand the embankment carrying the roadway or track.

AASHTO: American Association of State Highway and Transportation Officials. Aprofessional organization advancing highway design and construction by establishingengineering standards and specifications (formerly AASHO).

Bearing: (also shoe) a device that transfers loads from superstructure to substructure;can be fixed, expansion, or sliding with many subtypes of each; usually allowsmovement, especially horizontally due to thermal expansion. Some bridge typesdesigned without bearings.

Cantilever: projecting beam or structure anchored at one end to a pier and projectingover space to be bridged; allows bridge erection without falsework; trusses, plategirders and box girders can be built as cantilever bridges.

Car Float Barge: a very large barge equipped with tracks designed to ferry railroadcars across un-bridged waterways such as New York Harbor.

Continuous girder: a girder supported at three or more points; bending forces in thecenter of the span are reduced by opposite forces acting at the piers.

Dead load: weight of all the parts of the bridge and any imposed fixed loads on thebridge such as tracks, lighting, utility lines; see live load

Deck: floor or roadway of a bridge, often reinforced concrete; structural function is todistribute loads transversely; carried by or integrated with primary structural memberssuch as stringers and girders.

Deck bridge: bridge with deck above superstructure.

Falsework: temporary wood or steel structure erected like scaffolding to supportconstruction of a bridge; called centering when used for arches.

Field splicing: the joining of sections of a girder or other structural member of a bridgewith rivets, bolts or welding at the bridge site.

Flange: the top or bottom member of a beam or girder that resists tension orcompression.

Haunch: an increase in the depth of a member, usually at points of support.


Live load: a temporary or moving load imposed on a bridge or structure by persons,vehicles, wind.

Moment: the tendency to cause rotation around a point or axis; i.e., a bending momenttends to produce bending in a beam.

Moment distribution method: structural analysis method for indeterminate structureslike continuous beams using a series of approximate solutions repeatedly to obtainincreasingly smaller corrections.

Photoelastic analysis: a method of observing stress patterns in certain transparentmaterials using polarized light; used to analyze plastic models of bridges and predictbehavior under various loads.

Plate girder: a type of beam; see figure on page 16.

Prestressed concrete: concrete strengthened by the application of tensile force to thereinforcing tendons, either before the concrete has hardened (pre-tensioned) or after(post-tensioned).

Reversal stresses: stresses in members that change from tension to compression or viceversa; early continuous structures were shunned by some who considered themsusceptible to dangerous stress reversals resulting from differential settlement of thesubstructure.

Rigid-frame bridge: usually concrete, deck and abutments are rigidly joined; abutmentsfunction as legs to resist deck loads through torsional strains transmitted by the rigidconnection; overturning forces on abutments are resisted by deck.

Screed: a device used for spreading and striking-off fresh concrete to achieve a uniformsurface of desired slope and grade.

Simple beam: a beam with its ends free and resting on only two supports.

Simple span bridge: a bridge consisting of beams or elements that begin at one supportand end at an adjacent support

Statically indeterminate: structures that cannot be structurally analyzed by theprinciples of statics.

Substructure: the piers and abutments and their foundations, which support thesuperstructure and transmit the loads to the soil or rock.


Superstructure: the portion of a bridge above the piers and abutments; purpose is tocarry the deck across the obstruction being bridged.

Through or thru bridge: bridge with the deck passing through the superstructure.

Truss: a jointed structure made up of individual members arranged and connected,usually in a triangular pattern, so as to support longer spans


BIBLIOGRAPHY

Binckley, George S.1920 Art In Structures. Engineering News-Record, November 25, p. 1024.

Boynton, R. M.1958 Longest Plate Girder Span in Western Hemisphere Carries Turnpike Through

New Haven. Civil Engineering, February, pp. 36-39.

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Morris GoodkindChief Bridge Engineer - New Jersey Highway Department

1925-1955

Morris Goodkind was born in New York Cityin 1888 and graduated from ColumbiaUniversity in 1910 with a degree in civilEngineering. Following school, he workedwith the city of New York preparing plans forthe subway system. He joined the engineeringfirm of Albert Lucius in 1912 as an assistantengineer. Lucius had engineered elevatedrailway systems for New York and Brooklynin the late 1800s, and was specializing in thedesign of railroad bridges when Goodkindjoined him. Goodkind worked in Lucius'soffice between 1912 and 1914, andundoubtedly it was here that his interest andskills in bridge design were first honed.

During his early career years, Goodkindmoved between jobs in the public and privatesector. He worked for New York's InterboroRapid Transit Corporation and the J.G. WhiteEngineering Corporation. From 1919 to 1922,he worked as county bridge engineer forMercer County, New Jersey.

In 1922, Goodkind joined the New Jersey Highway Department as general supervisor of bridges. Hewas named Chief Bridge Engineer in 1925, a position he held until his retirement in 1955. Hereceived numerous awards and honors for his work over the course of his career with the state. Hismost prestigious bridge award was the Phoebe Hobson Fowler Medal, given by the American Societyof Civil engineers for his design of the College Bridge, a multi-span concrete arch carrying U.S.Route 1 over the Raritan River. The bridge has since been renamed the Morris Goodkind MemorialBridge.

Goodkind also won several "most beautiful bridge of the year" awards, given annually by theAmerican Institute of Steel Construction. Among the winners were Oceanic Bridge over theNavesink River (1940); Passaic River Bridge between Newark and Kearney (1941); and AbseconBoulevard Bridge in Atlantic City (1946). During World War II, Goodkind consulted for the WarDepartment, aiding the Army Corps of Engineers in bridge design and construction. He was awardedthe Tau Beta Pi Achievement Certificate from Rutgers in 1948 and an honorary Doctor ofEngineering degree from Newark College of Engineering in 1950. He served as Consulting BridgeEngineer for the building of the Garden State Parkway in the early 1950s. After retirement from theHighway Department in 1955, he was a partner in the firm of Goodkind and O'Dea, which currentlyoperates under the name of Dewberry-Goodkind, Inc. In 1958, Goodkind was granted the EgelstonMedal by Columbia University, their highest award for engineering achievements. Morris Goodkinddied September 5, 1968.

Morris Goodkind (facing camera) inspecting construction of Edison Bridge, 1939.

Construction of the Edison Bridge, 1940.Source: New Jersey Department of Transportation.

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Documents

The History and Technology of the Edison Bridge & Driscoll Bridge